Magneto-inductive flow measuring devices use for volumetric flow measurement the principle of electrodynamic induction: Charge carriers of the medium moved perpendicularly to a magnetic field induce a voltage in the measuring electrodes likewise arranged essentially perpendicularly to the flow direction of the medium. This measurement voltage induced in the measuring electrodes is proportional to the flow velocity of the medium averaged over the cross section of the measuring tube; such voltage is, thus, proportional to volume flow. In the case of known density of the medium, it is, moreover, possible to give the mass flow of the medium flowing through the measuring tube. The measuring electrodes are usually coupled with the medium galvanically or capacitively.
In connection with determining and/or monitoring volume flow by means of a magneto-inductive measuring device, the trend is increasingly in the direction of making available to the user, besides the volume flow, also information concerning the functional ability of the measuring device. The current catchword in this connection is ‘Predictive Maintenance’. The goal of these efforts is, in the end, to prevent, or reduce to a minimum, measuring device downtime.